1. Field of the Invention
This invention relates to a contact to be used for contacting with a terminal of an electric part such as an IC package.
2. Description of the Prior Art
A conventional contact 1, as shown in FIG. 9, often used in a socket for an IC, etc. comprises a supporting portion 2 extending in a horizontal direction, a terminal portion 3 extending downward continuously from the supporting portion 2 in order to be contacted with a circuit board or the like, a spring portion 4 disposed above the supporting portion in such a manner as to be continuous therefrom and curved into a horizontal generally U-shape, and a mount contact portion 5 formed on a free end of the spring portion in order to exert a vertical resiliency thereto and adapted to receive thereon an external terminal of an IC, the mount contact portion 5 being displaced downward while flexing the U-shaped spring portion 4 when the terminal of an electric part is contacted thereon and pressure is exerted thereto, so that the mount contact portion 5 is pressure contacted wtih the terminal of the electric part by reaction thereof.
In recent years, with the development of electronics manufacturing techniques, a small size of an IC socket is in demand. Furthermore, miniaturization of the contacts in an IC socket and of an external terminal of an IC has progressed, and as a result, achievement of a reliable contact relation therebetween is increasingly in demand at present. However, the conventional contact of the type in which a terminal of an electric part is contacted thereon in order to obtain an electric contact relation therebetween has such shortcomings that when the horizontal U-shaped spring portion is displaced in a vertical direction against its resiliency in order to exert contact pressure to the contact portion, the contact portion is disconnected from the external terminal of the IC because the contact portion has components which are excessively displaced forward and backward while it is itself displacing downward.
Since the space for accommodating the horizontal generally U-shaped spring portion is limited, even if the configuration of the spring portion is changed in order to reduce the amount of displacement of the contact portion in the forward and backward direction, control of the displacement of the contact portion in the forward and backward direction owing to the change in configuration thereof is necessarily limited.
Also, a conventional IC package called a TAB package has such shortcomings that since an external terminal thereof is a Cu foil which is soft, the strength thereof is very low and when the contact portion of the contact is displaced in an upward or downward direction, it is moved forward and backward while itself being friction contacted with the Cu foil, to thereby cause the weak external terminal to be deformed.